1. Field of the Invention
The present invention relates to the field of aeronautics and aircraft design, and provides a novel design particularly suited for model or toy aircraft.
2. Description of the Related Art
Model aircraft have been known for many years, and generally are designed to resemble full sized aircraft. That is, model aircraft have generally consisted of an elongate fuselage, with a central wing extending laterally out from the fuselage, and a tail assembly at the aft end of the fuselage. The tail assembly will generally consist of a vertical tail on which a vertical rudder is mounted, and short horizontal tail wings extending from either the aft end of the fuselage, or the top end of the tail. The elevators, controlling climb and decent angles, are mounted on the horizontal tail wings. Ailerons, controlling pitch and roll are mounted on the central wings, and are used, with the rudder, to steer the aircraft by rolling it while turning.
Alternatively, as shown in commonly assigned U.S. Pat. No. 6,612,893, steering may be accomplished by controlling the relative rates of revolution of each of a pair of wing-mounted engines.
It is known, moreover, to utilize electric motors to power the propellers or model aircraft, and this is shown in the aforementioned U.S. Pat. No. 6,612,893. Aircraft engines, for either full scale, or toy aircraft, may, depending on the overall design of the aircraft, be mounted in front of the main wing, on the wing, or behind the wing. In the former two configurations, the engine mount propellers known as tractor propellers, and in the later case, the propellers are known as pusher propellers. Propellers are generally mounted so as to be perpendicular to the longitudinal axis of the forward direction of flight. Lift is achieved by the flow of air over and under the wing surfaces. The wing surfaces are shaped so as to provide lift by creating downwash, an area of low pressure above the wing, and an area of high pressure below the wing, as the wing is moving through the air. If the speed of the aircraft through the air decreases below a critical velocity, the aircraft will loose lift and stall when the air pressure difference above and below the wings falls below a critical level. Stall will also occur in traditional designs, if the angle of attack of the wing, relative to the direction of flight, is increased beyond a critical point, usually about 15°.
It is also known to utilize surfaces other than wing surfaces, to generate lift. This can be accomplished by blending the fuselage into the central wings, thereby creating an all wing design, such as is exemplified by the well known B-2 bomber of the U.S. Air Force. Alternatively, a pair of pontoons or the like may be provided, with a flattened fuselage extending therebetween that can act like a wing. This design is shown in U.S. Pat. No. 5,273,238 to Sato, which teaches a twin-hull seaplane that also includes a traditional wing mounted above the fuselage. A wide flat fuselage and downwardly extending pontoons will assist in ground effect flight. Ground effect flight is a flight close to a ground or water surface, and uses the proximity of the surface to increase lift by decreasing the pressure above the wing, and increasing the air pressure below the wing. In order to transition from surface effect aided flight to ordinary flight, a large amount of thrust or downwardly vectored thrust is generally required.
The basic form of a hydroplane racing boat is well known. Generically, such a boat consists of a tunnel hull to which pontoons or sponsons are attached. The propulsive force is provided by a small submerged or semi-submerged propeller at the aft end of the tunnel hull centerbody. In high speed racing operation, the hull lifts up and hydroplanes on the sponsons. When this happens the hydrodynamic drag is dramatically reduced and relatively high speeds over water are possible. In this mode, the horizontal tail and supporting vertical fins or stabilizers provide some inherent static stability, which passively makes the boat more stable at high speed. For directional control a submerged rudder is used. Occasionally, hydroplanes crash in spectacular accidents after lifting completely off the water and losing all control. Hydroplane racing boats are not designed for controlled flight in air.
For high-speed flight on water, wing-in-ground effect vehicles (WIGs) and WIG ships sometimes called ekranoplans have been studied. These vehicles depend on lift from a wing to ride out of the water at high speed and skim the water's surface on sponsons or on a main centerline hull or fuselage. These concepts are not designed for operation on land or for flight out-of-ground effect. Moreover, WIGs cannot fly stationary in a hover.
The hovercraft or air-cushion vehicle (ACV) rides on an air cushion supplied by an enclosed plenum chamber that requires continuous contact with a smooth surface. Hovercraft cannot fly or hover.
For flight in air, there are two popular forms. The conventional aircraft configuration employing a wing with or without additional lifting surfaces, and the helicopter, generally and collectively called fixed-wing and rotary-wing aircraft. Although there are many flight vehicles that can be broadly classified as fixed-wing or rotary-wing aircraft, as well as other categories too numerous to mention, none of them appear similar to the basic forms of the model aircraft described herein, a hydroplane racing boat.
None of the above-mentioned vehicles resemble the model aircraft described by the applicants herein, which is a hydroplane racing boat with the ability to (1) skim the surface on land like a hovercraft, (2) hydroplane on water like a hydroplane racing boat, (3) take off and fly like a conventional fixed-wing aircraft and (4) stop in flight and hover like a helicopter. A vehicle capable of these modes of operation has been overlooked by prior innovators and is described by the applicants herein.